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Letters Patent No. 66,763, dated Julyll, 1867.

IMPROVEMENT IN MAGHINBS POR CUTTING DOVE-TAIIIS.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, CALVIN YOUNG, of Auburn, in the county of'` Cayuga,and State ot"New York, have invented certain new anduseful improvementsin Machines for Cutting Dove-Tails, suoli as are used in the frontsorbaoks of drawers, and other similar purposes; and I do hereby declarethe following to be a full, clear, and exact description ofthe same,reference being had tothe accompanying drawings, making a part ofthisfspecification, in whiehv Figure 1 representsa front view of themachine.

Figure 2 represents a side view or elevation; and i Figure .3represents` the cutting devices, separate from the machine', thespreading of the chisels being shown in red lines.

Similar letters oi' reference, where they occur inthe separateigureadenote like parts in all the drawings.

I am aware that a hollow chisel with rectangular sides, and aYboringinstrument working through such hollow chisel, has long been inuse. And I am further aware that dove-tails have been sawed in the endsof boards, buts'uch dove-4tailseXtend clear Vthrough the wood, and arecalled open dove-tails, whilst my object is to make secret orclosed-dove=tails, that is, dove-tails cut into but not through thewood, such as are used in making the fronts and backs of bureaus andother drawers. i

And my invention consists,rst, in the use of4 a hollow chisel withbevelled sides, and encorV more boring instruments working through thesamc,so as to cut a trapezoidal shaped opening into the end or edge of apiece of wood that is, an o enin of the forni of a lain four-sided fiure havinU-'two of its o osite sides arallel and P g P g e PP P theother two not parallel.

' And my invention further consists in the use of a bisected, or of twochisels, which act as one instrument or as two instruments, as the casemay be, they being so arranged and controlled as that they may be usedas.

one tool to cut down thesquare wall of adove-tail, and then to be spreadout and drawn in, so as to clean and 'cut out the oblique or under-cutwalls of the dove-tail.

To enable others skilled in the art to make and use my invention, I willproceed to describe the same with reference to the drawings.

0n a stand-or frame, A, isenounted a box or bearing, B, for supporting ashaft, C, which has a pulley,vD, upon it, by which it may he turned hyabelt or band from any first moving power, said shaft, besideits'revolving motion in said bea-ring,` having also an end motion, `fora purpose to be hereafter described. E isa slidtng head, which is movedback and forth on or in ways or guides a, so as to move in a true line.This head E is moved forwardand back by a lever, F, which is pivoted atto a stationary part of the machine, and the 4short arm of which worksin a slot in the under side 'of the head, so as to freely move itwithout cramping or straining,

said head on or in its ways or guides; and the other or long arm ofwhich lever extends forward to or near to the position occupied by theattendant on the machine, so that he may readily grasp and operate it tomove the head as may be required. To the front part of this moving headE is connected or adjustably attached a hollow chisel, c, the top andbottom of which are parallel, but of unequal lengths, and the sides ofwhich are not parallel, (being bevelled,) but of equal le1ig'ths,or of atrapezoidal form, and through this peculiarly-shaped hollow chisel worksa boring tool, e, which is upon the shaft C, and revolved by said shaft.The chisel c may be ofthe size and form ofthe end ofthe dove-tail to becut, and when the dove-tail has greater length than height, which isgenerally the case, two or more boring instruments may work inconnection with it, each turned by a shaft similar to C, or a series ofboring tools may be geared together and operate from a single shaft, orfrom one belt, in a manner well known to mechanicians. The 'shaft andits auger move`back and forth with the head and'hollow chisel, and insetting the-auger, Vits cutting lipsv are flush with the edges of thehollow chisel,or thereabouts,the`g1mlet point ofthe auger slightlyprotruding therefrom. The auger or angers cut away the mass of wood thatis removed to form the dove-tail, whilst the chisel gives the square orangular corners to the dove-tail, and the two combined cut or shape fourof the sides of the dove-tail, viz, the top, botton1,`and sides, butthere is a fifth side, or the back wall ofthe dove-tail, still to be cutout or formed, and this fifth sideV runs under in both directions, andmust be removed by an instrument working in a vertical plane, andwithout cut` ting or injuring the overhanging wood. This I accomplish asfollows: In theside pieces G I arrange a gate, H,

es, 'rea which can be moved up and down in a vertical plane by means ofav lever, I,hung to the main frame at-d, and which may be operated bythe foot of the attendant occupying a position at the front of themachine. To this lever I is attached a cross-head or arm, [Land fromeach end of this cross-arm J a connecting-rod, f, extends' up', and isattached to across-head, g, that carries the gate H, and by means ofwhich connections said gate is moved in'its ways or guides L. On thefront or face ofthe sliding-gateV G are pivotcd as at z' z', two chiselsjj, which operate as one or two, as the case may be, and as will beexplained. I As these chisels are brought down by the foot of theoperator uponfthe lever I, they cut down thcback wall of the dove-tail;and when the lever is released, it may'riserand' raise up the gate andchisels by the reaction of a spring. But it is necessary lin dressing orcleaning out the corners of the dove-tail, that the thisels should havea lateral motion so as to worli under the overhanging wood, and thenAreturn to their upright or vertical position, so as to be withdrawnfrom the dove-tail.. This I accomplish as follows: i To the rear of thegate is pivoted, as at m, a lever, K, which extends upwardsso as to' bereadily caught and operated by the attendant from his position or stand,and to this lever K is connected (by a slot and pin, or other link orpivoted connectiom) a block, Ic, carrying two pins n n, which, by themovement of said lever, may be protruded through slots Z Z in said gate,so as to stand in the path of the 'upper curved ends of the chisels jj,andA being stationary, the chisels, in passing these studs or pins,.arecaused to move laterally upon their pivots it', but are returned,immediately after they begin to rise, by the spring o, which forces thecutting edges of the chisels together. Sb long as the pins n n areprotruded through the gate, the chisels will thus be spread apart,.anddescend i-n an oblique manner into and under the corners of thedove-tail, and clean' out the excess of wood therein. When the pins laredrawn back and out of action, the chisels actas one chisel, rising andfalling in a vertical plane without any lateral motion. VL islasliding-table, upon which the piece of wood M that is to be dove-tailedis clamped by the clamps N and screws pp. The piece of wood having beenmoved up into proper position, 4the lever-F is moved down, which bringsup'the hollow chisel c and auger e into action, cutting and boring intothe end of the piece of wood to the extent for whichtheyhad beenpreviously set or adjusted. When', by a single or two or more ofsuch'op'erations, they have removed their .share of `the wood, they arethrown back out of action, and` the lcliisels j j brought into actionbythe lever I, and which-cut down the back wall of the dove-tail, as oneinstrument, until they have arrived at or near theend ofthe dove-tail,or Where it runs under the overhanging wood.` Then the operator, by thelever K, brings the pins n n'into action, and the chisels are thenthrown out laterally, asrshown by the red lines-in ig. 3, and under-cutVor clean out the corners ofthe dove-tail, immediately after theircutting opera,- tion returning to their vertical position by means ofthespring o. The several adjustments necessary for adapting the machineformaking dove-tails larger or smaller need not be mentioned, as suchcapabilities are obvious andcommon in many machines. The slot r in the'sliding-gate H, central between those ZZ, above mentioned, and the pins, protruding an'd operating therein,.is designed for closing the twochiscls jj, or bringing them together in case the spring o4 shouldfailto do so.

Having thus fully described my invention, what I lclaim therein as new,and desire Ato secure, by Letters Patent, is I I 1. The combinationof ahollow chisel, two of the sides of which are parallel, but of unequallengths, and the remaining two sides of which are not parallel, but areof equal'length, and one or more. angers working in. or through saidhollow chisel, for the purpose of cutting dove-tails, substantially inthe manner described.

2. I also claim, in combina-tion with two chisels, whose cutting edgesareheld together by a spring or yielding attachment, the studs or pinswhich, when moved into the path of the chisels, cause them tospread-laterally for the purpose of cutting down the back wall of adove-tail, and cleaning out the corners or under-cut portions,

substantially ,as described.

, CALVIN YOUNG.

Witnesses :i

JNO. B. RICHARDSON,

GEORGE W. KIRKPATRICK.

